I'm unable to create a shop page using bebuilder, I'm using the belottie theme. Please see the attached screenshot, it shows the admin panel where the page editor should be.
I created a page, assigned it under woocommerce as the shop page, and then tried editing it with bebuilder, now I can see the page but can't add elements and build it, as attached.
If you want to create a custom template for shop, please go to the templates, there you can edit that.
Please, follow this video tutorial to get familar with it.
Also, do not forget to assign the main shop page in WooCommerce settings.